Idle Problems...

[SuperSeanic]

ok i have a 93 CX with a y7 w/ y8 intake mani 5spd...this is how the car was when i got it...okay so ever since i got my car it has idled weird on cold start up..it will either idle rapidly at about 1500 w/ the cel on or surge between 1k and 2k w/ no cel...i checked out the cel and it flashed a 14 IACV...so i replaced the iacv with a used one off of ebay...that one didnt work...so i figured it was another bad iacv...so i just recently bought a brand new one from advance..and it still does it...so i tried resetting the ecu by disconnecting the battery and no luck...so i was wondering if anybody knows how to fix this...and if its bcuz the y7/y8 mani combo, will swapping to a y8 head fix it?...please help, thanks

[Rexinre]

A surge in idle could mean a few things.

Vacuumed leak
too much fuel
timing advanced to much
air bubbles in the coolant
blown head gasket


Start investigating.

[SuperSeanic]

but the thing is it only does it when warming up...when it gets warm it idles normal....except if i sit still for like 10 min it will surge once...and when the cel is on and i slowly accelerate...once i get to 1500rpm it will rapidly go up and down 1500-1600...if its in gear the car jerks pretty bad ((sucks))...

but if it was caused by any of those things..wouldnt it rapidly idle all the time..not just when warming up?...and im still getting the cel 14 iacv

[guest]

A surge in idle could mean a few things.

Vacuumed leak
too much fuel
timing advanced to much
air bubbles in the coolant
blown head gasket


Start investigating.

well, I just tuned my car and it was running super at idle, but it didn't surge at all..... When my timing has been way off the idle is fine too.

[Rexinre]

but the thing is it only does it when warming up...when it gets warm it idles normal....except if i sit still for like 10 min it will surge once...and when the cel is on and i slowly accelerate...once i get to 1500rpm it will rapidly go up and down 1500-1600...if its in gear the car jerks pretty bad ((sucks))...

but if it was caused by any of those things..wouldnt it rapidly idle all the time..not just when warming up?...and im still getting the cel 14 iacv

As far as the IACV are you 100% sure that the wire connectors didn't get mixed up? If I remember correctly there are 2 connectors that fit that sensor. Also (again if I remember correctly) there is a 2 wire IACV and a 3 wire... Maybe do a little search to see if you are using the correct one.

It could do it some times and it could do it all the time. Bottom line is something is messed up. I don't make this stuff up, its happend to me before and thats how I know.

First time it was a big vacuume leak. Then it took me a year to find out it was too much fuel and the timing was advanced to far. Now she runs perfect.

[JDMCivic00Ex]

well i have the exact same problem.. i mean exact my car does everything that is happening to super. and i have not found the problem yet either.. checked for vac leak came up with nothing. cleaned out the IACV that wasn't it. i know mine can't be fuel i'm below 1/4. haven't did coolant(which i think might be the problem since it reserve was empty when i looked) is there any easy way to get out air bubbles without flushing? also it could be timing since my Acceleration from 0-20 is terrible and it wasn't this way before.

edit: also i have an auto d16y8 so it's prob not the y7 y8 combo.

superseanic if you find out what's wrong with yours could you let me know it might be the same problem with mine thanks alot

[areskzc]

I'm running throu idle problems too... but mine are more complicated since new injectors, new rom configurations are involved so It's a large list to check tooo..

Check.

Fuel filter clogged
IACV (dirty or poor connection)
Blown HG (hope it's not buddy)
Vacum leak
IM gasket leak
Incorrect Timing
Faulty distributor or coil
Injectors too dirty

[sage]

well i have the exact same problem.. i mean exact my car does everything that is happening to super. and i have not found the problem yet either.. checked for vac leak came up with nothing. cleaned out the IACV that wasn't it. i know mine can't be fuel i'm below 1/4. haven't did coolant(which i think might be the problem since it reserve was empty when i looked) is there any easy way to get out air bubbles without flushing? also it could be timing since my Acceleration from 0-20 is terrible and it wasn't this way before.

edit: also i have an auto d16y8 so it's prob not the y7 y8 combo.

superseanic if you find out what's wrong with yours could you let me know it might be the same problem with mine thanks alot

easiest way insted of flushing is bleeding it.

[1990reds13]

easiest way insted of flushing is bleeding it.

how do you go about doing this?

[EGhatchintheham]

The IACV has the exact same plug as the evap sensor on the intake manifold. The wires to the sensors also get the same voltage (i was having an erratic idle when I fist swapped in my d15b). The d15b doesn't have the evap sensor on the intake mani so i accidentally connected the evap sensor plug to the IACV. I had an erratic idle and my off-idle throttle response was really sudden as well. You could have the plugs on those two sensors switched.

[SuperSeanic]

The IACV has the exact same plug as the evap sensor on the intake manifold. The wires to the sensors also get the same voltage (i was having an erratic idle when I fist swapped in my d15b). The d15b doesn't have the evap sensor on the intake mani so i accidentally connected the evap sensor plug to the IACV. I had an erratic idle and my off-idle throttle response was really sudden as well. You could have the plugs on those two sensors switched.

this was the exact problem, thank you so much...i kinda figured it would be something dumb as 2 identical plugs switched around...the CEL is off and everything...thanks again

[sage]

how do you go about doing this?

with your car running and heat on blast where your top hose meets the motor there is a little nipple use a wrench and open it when water comes out close it and repeat til when you open only water comes out and no air.

[Rexinre]

this was the exact problem, thank you so much...i kinda figured it would be something dumb as 2 identical plugs switched around...the CEL is off and everything...thanks again


Glad we helped you figure it out.

[JDMCivic00Ex]

wow i hope i didn't swap plugs between mine. i'm almost sure i didn't. but i have only 3 things left to check and after that its goin to a mechanic.

fuel filter clogged.
injectors too dirty.
timing.

so lets hope one of those is it :TU:

[pimpindistress]

lol i swap up plugs all the time , little trick i do now is get a fine point black marker and a rag and label every plug when removing the harness from the old engine . it makes things go alot smoother , also watch out for MAP and TPS also the same plugs with very similar colored wires

[SuperSeanic]

lol i swap up plugs all the time , little trick i do now is get a fine point black marker and a rag and label every plug when removing the harness from the old engine . it makes things go alot smoother , also watch out for MAP and TPS also the same plugs with very similar colored wires

yeah thats what i would've done..but the dumbass who owned the car before me obviously didnt know what he was doing

[JDMCivic00Ex]

well i just thought i'd update this for others who lead into this problem.
i finally got to take it to the shop that my buddy owns and we both looked/fixed it.

the cel 14 for IACV was because of a blown headgasket. so that was fixed. also timing was wayyyy off and that was also fixed. now for the jumpy idle in park/neutral.. he said to me that is seems to happen on hondas when you get a cai. he said that a prelude down there had the same exact problem and they havent been able to fix it. so any help with that is still appreciated. no more cel tho so its good. only thing i don't liek is the jumpy rpms fromm 1000-2000 back and forth while in park.. doesnt sound good when parked out somewhere.

[Haysoos]

He's using a y8 mani in a 93, right? Correct me if I'm wrong, but doesn't the y8 use a 3 wire IACV and the 92-95 civics use a 2 wire?

Could be 100% wrong, but I just thought i would ask...

[projectEK]

I'm running throu idle problems too... but mine are more complicated since new injectors, new rom configurations are involved so It's a large list to check tooo..

Check.

Fuel filter clogged
IACV (dirty or poor connection)
Blown HG (hope it's not buddy)
Vacum leak
IM gasket leak
Incorrect Timing
Faulty distributor or coil
Injectors too dirty


That's a lot of good info there +1 rep for you

[SOHCinWA]

9 times out of 10 it is vacuum leak on the intake.. Did you change or replace anything recently??